1. Field of the Invention
This invention relates to an arming unit retention mechanism and, more particularly, relates to electro-mechanical arming units.
2. Description of the Related Art
Arming unit retention mechanisms are used in conjunction with bomb racks, aircraft pylon, or other weapons release systems with weapons which are armed by the pulling of a lanyard. In these arming unit systems, a hook or plunger retains the weapon lanyard such that when the weapon is released, the lanyard is pulled, and the weapon is armed by the pulling of the lanyard. Additionally, at times it is desired to release an unarmed weapon. These arming unit systems permit the hook to be disengaged from the weapon lanyard such that when the weapon is released, the lanyard is not pulled, and the weapon is released unarmed.
In addition to providing the arming function described above, arming units are also used to accommodate high drag or low drag bomb release. In this case, the weapon has fins adapted to be extended and retracted. In the extended position, the fins provide high wind resistance or drag. In the retracted position, the fins provide low wind resistance or drag. In these systems, the hook or plunger retains the drag lanyard such that when the weapon is released, the drag lanyard is pulled, and the fins are extended by the pulling of the lanyard. Alternately, the hook is disengaged from the drag lanyard such that when the weapon is released, the drag lanyard is not pulled, and the fins remain retracted.
Two types of arming unit (hereinafter xe2x80x9cAUxe2x80x9d) retention mechanisms are commonly known in the art, conventional AU technology and zero retention force (hereinafter xe2x80x9cZRFxe2x80x9d) AU technology.
As described above, at times it is desired to release an unarmed weapon. In conventional AU mechanisms, in order to release an unarmed weapon the user must provide the force necessary (typically 10-12 pounds of force) to disengage the hook from the lanyard. If the user is unable to provide this force, or if the mechanism fails for whatever reason, the AU does not open and an armed weapon may be released instead of the desired unarmed weapon.
In ZRF AU mechanisms, the lanyard is disengaged by the driving of a mechanical linkage opening the lanyard hook. If this mechanism fails for whatever reason, the ZRF AU does not open and an armed weapon is released instead of the desired unarmed weapon.
Both the conventional AU and the ZRF AU require a force external to the AU (e.g. the user or driving of a mechanical linkage) to release the lanyard. Therefore, there is a continuing need for an electrically operated arming unit retention mechanism that is driven by pre-existing weapons system signals, and that removes the need for external forces to lock the arming unit.
Prior art AU""s, as shown in FIGS. 1 through 3, are used in conjunction with bomb racks and operate in three modes: Normal mode, Armed/Locked mode (hereinafter xe2x80x9cLockedxe2x80x9d), and Open mode. Weapon release systems utilize an arming signal 20 to signal the mode to the AU. Weapon release systems also have a firing signal 21 to provide power to the bomb rack to release the weapon.
The prior art ZRF AU 5 shown in FIG. 1 is in the Normal mode. In the Normal mode, a weapon 10 is loaded into a bomb rack (not shown) with arming lanyard 8 disposed between a lanyard hook 9 and a lanyard plunger 11 of ZRF AU 5. Lanyard plunger 11 is operable to extend into contact with lanyard hook 9 and is operable to retract into ZRF 5. In the Normal mode, lanyard plunger 11 is extended into lanyard hook 9. engaging arming lanyard 8 between lanyard plunger 11 and lanyard hook 9.
Lanyard plunger 11 is operable to extend and retract via the movement of an arming linkage 12. A bomb rack (not shown) is adapted to provide a linkage force 14 to arming linkage 12 disposed on ZRF 5. Linkage force 14 acts to pivot arming linkage 12 about one of two pivot points. A mechanism 6 (not shown) within ZRF 5 is adapted to allow arming linkage 12 to pivot about either an arming pivot point 13 or an unarming pivot point 15.
In the Open mode, shown in FIG. 2, mechanism 6 operates to allow arming linkage 12 to pivot about unarming pivot point 15. When pivoting about unarming pivot point 15, arming linkage 12 retracts lanyard plunger 11 from lanyard hook 9, thus disengaging lanyard 8 from ZRF 5. The Open mode permits release of an unarmed weapon 10. To achieve the Open mode, the user does not provide an arming signal 20 to ZRF S via wire terminals 7. When ZRF 5 receives linkage force 14 to arming linkage 12 upon weapon release, the ZRF 5 arming linkage, by default, pivots about unarming pivot point 15, causing the release of the unarmed weapon 10.
In the Locked mode, shown in FIG. 3, mechanism 6 operates to allow arming linkage 12 to pivot about arming pivot point 13. When pivoting about arming pivot point 13, arming linkage 12 does not retract lanyard plunger 11 from lanyard hook 9, thus leaving lanyard 8 engaged to ZRF 5. The Locked mode permits release of an armed weapon 10. To achieve the Locked mode, the user provides arming signal 20 to ZRF 5 via wire terminals 7 to activate the Locked mode. ZRF 5 receives arming signal 20 which activates mechanism 6 to allow arming linkage 12 to pivot about arming pivot point 13. The bomb rack is opened upon the user providing firing signal 21. Firing signal 21 causes the bomb rack to provide linkage force 14 to arming linkage 12. Linkage force 14 pivots arming linkage 12 about arming pivot point 13, causing the release of the armed weapon 10.
Additionally, the current equipment in the field is equipped with either one of the two above mentioned systems. Accordingly, there is a continuing need for an electrically operated arming unit retention mechanism which can be retrofitted to the existing equipment.
The teachings of this invention relate to logic circuitry for a weapon arming unit, the circuitry being driven by pre-existing weapons system signals, and that beneficially removes the need for external forces to open the arming unit for safe release.
The apparatus of the present invention provides for an electrical controlled arming unit which removes the need for an external force to operate the unit. The present invention uses a logic circuit that is driven by the pre-existing weapons system signals to remove the need for external forces to open the arming unit.